The present invention relates generally to medical graft devices containing submucosa tissue. In particular, one embodiment of the present invention relates to a medical device comprising a collagen layer including submucosa, wherein the layer has a highly deformable, meshed structure.
As further background, certain extracellular matrix materials, including submucosa tissues, are known tissue graft materials. See, e.g., U.S. Pat. Nos. 4,902,508, 4,956,178, 5,281,422, 5,372,821, 5,554,389, 6,099,567, and 6,206,931. As taught in these patents, submucosa tissues from various biological structures such as small intestine, stomach, and the urinary bladder provide predominantly collagenous layers useful in a variety of surgical procedures where tissue support and/or ingrowth are desired. As one example, sheet-form submucosa tissue has been suggested and used as a wound dressing.
Modified tissue graft constructs, including certain perforated forms thereof, are also known. For example, U.S. Pat. Nos. 5,755,791 and 5,997,575 teach certain perforated submucosal tissue graft constructs. As taught in these patents, multilaminate submucosal tissue graft constructs may accumulate tissue fluid in cyst-like pockets between adjacent layers after implantation in soft tissue locations. To reduce the occurrence of such pockets, these patents teach that the multi-layer submucosa graft constructs can be perforated.
Despite prior teaching of certain modified forms of submucosa grafts, needs remain for improved modified forms thereof, having particular utility for example in the treatment of open cutaneous wounds, including burns. The present invention is addressed to these needs.